The present invention relates to a manufacturing device and manufacturing method for a heat sink that has a base and heat-radiating fins. The heat sink that has base and heat-radiating fins and that is manufactured by the manufacturing device and manufacturing method of this invention can be used not only for heat sinks for the heat radiation and cooling of heat-generating electronic components used in electronic devices, but also for heat-radiation cooling in all fields that require heat dissipation.
The ever smaller size and higher degree of integration of the semiconductor chips used in computers, game machines, audio equipment, and other electronic devices have led to much faster processing, and with it a very high heat generation density. Heat sinks in which a base and heat-radiating fins are formed integrally are widely used as a means for dissipating the heat that is emitted by personal computers, game machines, audio equipment, and other electronic devices that have semiconductor chips or other components whose heat generation density has thus increased. In a heat sink constructed with a base and heat-radiating fins formed integrally, weight can be reduced and the heat-radiating surface can be increased.
The manufacturing method and manufacturing device for manufacturing heat sinks in which the base and heat-radiating fins are formed integrally are shown in FIG. 2 which diagrammatically shows a conventional device for manufacturing heat sinks. FIG. 1 shows a heat sink 31 manufactured by a conventional manufacturing device. FIG. 3 is an enlarged view of the fins of a heat sink manufactured by a conventional manufacturing device.
Die cast 34 shown in FIG. 2 consists of a fixed mold 36 and a movable mold 35. Mold 35 moves in the vertical direction and a cavity 37 which consists of a cavity 39 for the base and a cavity 38 for the heat-radiating fins. Movable mold 35 can move up and down as indicated by arrow C in the diagram of FIG. 2.
In heat dissipation using a heat sink in which a base and heat-radiating fins are formed integrally, the heat emitted by the heat source is first received by the thermally conductive base, then the heat from the heat source is dissipated by the heat-radiating fins that are provided adjacent to and integrally with the thermally conductive base that receives the heat.
But with a conventional manufacturing device, if the heat sink is formed integrally so that in the diecast the heat-radiating fins are perpendicular to the base, the height of the fins, the spacing between them, and other conditions of the shape of the fins are subject to constraints, which presents the problem that fins that have adequate heat dissipation effect cannot be obtained. That is, when molten metal is injected into cavity 37 and the heat sink is formed integrally, when removing the movable mold that is positioned above the fixed mold and moves up and down in the direction of arrow C, if the height exceeds the prescribed height, cracking and other damage to the fins occurs, making it difficult to manufacture an integrally formed heat sink.
The spacing between fins becomes large if, in order to make it easy to remove the movable mold, each fin 33 of the heat-radiating fins integrally formed at the end of base 32 is formed with a prescribed taper angle so that its width narrows toward its tip. Moreover, making the fins longer creates the problem that the strength of the heat-radiating fins is reduced. Because the movable mold is pulled out upwards after the heat sink has been formed, there is the problem that it is impossible to form on the heat-radiating fins any parts along the direction perpendicular to the direction in which the movable mold moves.
It is therefore an object of the present invention to provide a manufacturing device and a manufacturing method for a heat sink that has fins of various shapes, and also has the prescribed strength, high heat-radiating efficiency, and whose base and heat-radiating fins are formed integrally.
The inventors have carried out much diligent research in order to solve the above-identified previous problems. As a result, they have learned that, by combining a fixed mold, a movable mold that can move in the up-down direction (the first direction), and a slide mold that can move in the horizontal direction (the second direction), one can, manufacture a heat sink that has fins of various shapes, has the prescribed strength, has high heat-radiating efficiency, and whose base and heat-radiating fins are formed integrally. That is, by forming the mold split in the up-down and horizontal directions, using for the base a fixed mold and a movable mold that can move in the up-down direction and splitting the mold into a top and bottom, and using for the heat-radiating fins a fixed mold and a movable mold that can move in the up-down direction (the first direction) and a slide mold that can move in the horizontal direction (the second direction), one can manufacture a heat sink which can have fins of various shapes, have superior heat-radiating efficiency, and whose base and heat-radiating fins are formed integrally.
By pulling out the mold in the side direction of the fins of the heat-radiating fins horizontally, the pullout distance becomes short, and one can prevent any fin cracking or other damage even if the fins are high and narrowly spaced. Also by pulling out the mold in the side direction of the fins of the heat-radiating fins horizontally, the fins can be given various shapes including curves, and one can manufacture a heat sink of high heat-radiating efficiency whose base and heat-radiating fins are formed integrally.
The present invention was made, based on the discovery referred to above. According to a first aspect of the present invention, a heat sink manufacturing device includes a die casting machine that has a cavity for the heat sink consisting of a base and heat-radiating fins, and the die casting machine includes a fixed mold, a movable mold that can move in the up-down direction, and a slide mold that can move in the horizontal direction.
According to a second aspect of the present invention, a heat sink manufacturing device includes a die casting machine in which the base is formed by the fixed mold and the movable mold that can move in the up-down direction, and the heat-radiating fins are formed by the fixed mold, the movable mold and the slide mold.
In a heat sink manufacturing device according to a third aspect of the present invention, the slide mold has at least two parts that extend in the horizontal direction and are separate from each other.
In a heat sink manufacturing device according to a fourth aspect of the present invention, the parts that extend in the horizontal direction and are separate from each other consist of parts of polygonal cylinder shape.
In a heat sink manufacturing device according to a fifth aspect of the present invention, the parts that extend in the horizontal direction and are separate from each other consist of at least two curved parts.
In a heat sink manufacturing device according to a sixth aspect of the present invention, the vertical cross-section of said slide mold is of a lattice shape.
In a heat sink manufacturing device according to a seventh aspect of the present invention, the vertical cross-section of said slide mold consists of multiple parallel waveform shapes.
In a heat sink manufacturing device according to an eighth aspect of the present invention, a heat sink manufactured therein has a heat pipe.
A heat sink manufacturing method according to a first aspect of the present invention includes the steps of:
a step of preparing a die casting machine that has a cavity for a heat sink which consists of a first cavity for the base of the heat sink and a second cavity for heat-radiating fins of the heat sink, and that includes a fixed mold, a movable mold that can move in the up-down direction, and a slide mold that can move in the horizontal direction, wherein
a step of positioning the die casting machine so that the first cavity for the base should be formed by the fixed mold and the movable mold that can move in the up-down direction, and the second cavity for the heat-radiating fins should be formed by the fixed mold, the movable mold that can move in the up-down direction, and the slide mold,
a step of injecting molten metal into the cavity and cooling the metal to the prescribed temperature, and
a step of moving the movable mold up-down and moving the slide mold in the horizontal direction, to thereby manufacture the heat sink. In the heat sink manufacturing method according to a second aspect of the present invention, the slide mold may have at least two parts that extend in the horizontal direction and are separate from each other.
In the heat sink manufacturing method according to a third aspect of the present invention, the parts that extend in the horizontal direction and are separate from each other may consist of parts of polygonal cylinder shape.
In the heat sink manufacturing method according to a third aspect of the present invention, the parts that extend in the horizontal direction and are separate from each other may consist of at least two curved parts.
In the heat sink manufacturing method according to a fourth aspect of the present invention, the vertical cross-section of the slide mold may be of a lattice shape.
In the heat sink manufacturing method according to a fifth aspect of the present invention, the vertical cross-section of the slide mold may consist of multiple parallel waveform shapes.
In the heat sink manufacturing method according to a sixth aspect of the present invention, the heat sink may be manufactured to have a heat pipe.
In the heat sink manufacturing method according to a seventh aspect of the present invention, the movable mold may be moved up-down, and next, the slide mold may be moved in the horizontal direction.
In the heat sink manufacturing method according to an eighth aspect of the present invention, the slide mold may be moved in the horizontal direction, and next, the movable mold may be moved up-down.
In a heat sink according to a first aspect of the present invention, a heat sink is manufactured by a heat-sink manufacturing method having the following steps of: a step of preparing a die casting machine that has a cavity for a heat sink which consists of a first cavity for the base of the heat sink and a second cavity for heat-radiating fins of the heat sink, and that includes a fixed mold, a movable mold that can move in the up-down direction, and a slide mold that can move in the horizontal direction, wherein
a step of positioning the die casting machine so that the first cavity for the base should be formed by the fixed mold and the movable mold that can move in the up-down direction, and the second cavity for the heat-radiating fins should be formed by the fixed mold, the movable mold that can move in the up-down direction, and the slide mold,
a step of injecting molten metal into the cavity and cooling the metal to the prescribed temperature, and
a step of moving the movable mold up-down and moving the slide mold in the horizontal direction, to thereby manufacture the heat sink.
According to a second aspect of the present invention, a heat sink is manufactured by the manufacturing method in which the slide mold has at least two parts that extend in the horizontal direction and are separate from each other.